Sometimes, different words have the same meaning. Sometimes, one word has many different meanings. Usually, a reader can understand the meaning from the context. Sometimes, plain English is not sufficiently accurate to make sure that the text is clear. For example, think about the following sentence: The cost of each component is significant.

Three interpretations are possible:

The cost of each component is large. (The cost of each component is not necessarily important.)

The cost of each component is important. (The cost of each component is not necessarily large. Possibly, the cost is small, but millions of components are necessary.)

The cost of each component is both large and important.

To make text as clear as possible, a controlled language is necessary. A controlled language specifies the grammatical structures and the words that a writer can use. One controlled language is ASD Simplified Technical English.

In principle, the laws are good. However, no international standard specifies plain English. Therefore, some lawyers will probably become rich by arguing whether a particular text is plain English.

In the UK, three commercial organizations sell an approval service for plain English. Because no international standard specifies plain English, different organizations can give different evaluations for the same document.